A 23-year-old man has been warned he will almost certainly develop dementia after inheriting a rare genetic mutation.

Jordan Adams is thought to be the youngest person in Britain to find out that he will suffer early onset frontotemporal dementiaand Parkinson's Disease because of a faulty MAPT gene.

Although he currently shows no signs of illness, doctors have warned him he could lose the ability to walk, talk and feed himself at any time and could die in his 50s like his mother Geri who lost her life aged 52.

He has just one in 100 million chance that the mutation will not lead to dementia.

Mr Adams, an entrepreneur from Redditch, Worcestershire, said: "When I was told the diagnosis I was devastated. Nobody can prepare you for that. It's like a death sentence.

Woodsman Within limits. Most probably the young man's genes were damaged already before birth, inheriting this deficiency from his parents.

I know another (and different) example from my former home town. A severly malformed child was born to a family with a long history of incest. It lived miserably for a couple of years. There is nothing that poor child could have done.